Toy building block



FIG. 1 is an enlarged front perspective view of the toy building block showing my design.

FIG. 2 is an enlarged side elevation view thereof.

FIG. 3 is an environmental front perspective view illustrating four of the toy building block of my design assembled to form an ‘X’ and to which ornamental pins may be plug to the orifices of its front walls;

FIG. 4 is an environmental top view thereof;

FIG. 5 is an environmental front elevation view thereof; and,

FIG. 6 is an environmental side elevation view thereof.

The broken lines represent portions of the design that form no part of the claim. 

I claim the ornamental design for a toy building block, as shown and described. 